Flexible conduit



i No. 751,777. PATBNTED FEB. 9, 1904.

A. T. BLAGKLBR. FLEXIBLE CONDUIT.

APPLICATION FILED MAIL-1.4, 1903.

NO MODEL.

69%.QM & via M UNITED STATES Patented February 9, 1904.

PATENT OFFICE.

ARCHIBALD T. BLACKLER, OF MALDEN, MASSACHUSETTS, ASSIGNOR TO JAMES S.WVILSON, OF CHELSEA, MASSACHUSETTS.

FLEXIBLE CONDUIT.

SPECIFICATION forming'part of Letters Patent No. 751,777, dated February9, 1904. Application filed March 14, 1903. Serial No. l L7,7l9. (Nomodel.)

To ulZ whom it may concern:

Be it known that LARGHIBALD T. BLAOKLER, of Malden, in the county ofMiddlesex and State of Massachusetts, have invented certain new anduseful Improvements in Flexible Conduits, of which the following is aspecification.

This invention relates to the construction of flexible conduits ortubes, and particularly flexible conduits designed to contain andinsulate an electric wire or wires. Among the requisites of a goodconduit of this character are that it shall be of sufficient flexibilityto bend freely and resume its original shape when straightened again,that it shall not freely unravel or pull out at the end when a length iscut off, and that it shall pass a wire freely without causing the end ofthe wire to catch on the interior of the conduit. The conduit shouldalso be capable of being made by machine processes, so as to render itsmanufacture inexpensive.

The conduit forming the subject of my present invention, which I shallnow proceed to describe, combines the above characteristics by virtue ofits novel construction.

Of the accompanying drawings, Figure 1 represents an elevation of aflexible conduit constructed in accordance with my invention with thesuccessive layers or Wrappings partly unwound or turned back atdifferent points. Fig. 2 represents a transverse section of the conduit.Fig. 3 represents a longitudinal section on the line 3 3 of Fig. 1.

The same reference characters indicate the same parts in all thefigures.

The conduit, as shown, consists of a series of tubular layers, of whichthe inner tube 10 is constructed by interweaving a helical flat strip 11of a smooth, compact, flexible insulating material, such as thinfiber-board, with a series of longitudinal flat strips 12 12 of the sameor a similar material or materials. Ido not, however, confine myself tothe particular material mentioned. This weaving may be done in anysuitable manner, as by hand or by means of a circular loom for weavingtubes. The peculiarity of a conduit of the above-described constructionis that it will pass a wire freely without allowing the end of the wireto catch on the interior of the tube. The longi- 5o tudinal strips 12being parallel, or substantially so, to the length of the tube and of asmooth compact material form tracks on which the wire slides easily.

In the process of weaving the tube those portions of the circumferentialelements or convolutions of the helical strip 11 which lie exposed onthe inside of the tube between the exposed squares or patches of thelongitudinal strips lie in nearly the planes of the said squares orpatches or in more outward planes. Thus the abrupt bends 13 13 of thelongitudinal or warp strips give an easy transition to and from theintervening exposed portions of the helical weft-strip 11, so that thepassing wire is not allowed to engage the edges of the said strip 11. Asthestrips 11 12 are flat, smooth, and of a compact material, the end ofthe wire does not catch in them. This catching is not readily avoided inthe case of a tubular conduit whose interior has a warp or weft composedofthreads. A further advantage of the construction described is that ifthe tube is bent or kinked it will upon being straightened out resumesits original cross- 7 5 sectional shape, this being due to the fact thatboth warp and weft are composed of flat strips of a certain stiffnesswhich mutually support each other.

I have shown longitudinal threads 14: overlying the helical weft-strip11 on its outer side and located between it and the longitudinalwarp-strips 12 12, each thread passing in zigzag fashion back and forth,so as to include a pair of adjacent warp-strips. These threads 8 5 serveto interlock the warp and weft strips and prevent the helical weft-stripfrom unraveling or pulling out from the Warp-strips at the end of theconduit.

In the drawings the tube is shown some- 9 what more open-meshed than itneed be in practice for the purpose of fully displaying thelocking-threads 14.

15 is a helical winding or Wrapping of waterproof fabric which coversthe interstices of the tube 11 and protects the interior of said tubefrom the entrance of water or moisture.

16 17 are outer tubular layersof woven fabric to further protect theinner tube. After the outer layers are applied the outside of theconduit is preferably treated with a waterproofing compositionsuch aspitch, coal-tar, or other suitable preparationand is then dusted withmica. The wrapping 15 is of an adhesive material, such as rubber tape orfriction-cloth, wound on the tube 10 in a direction opposite to that ofthe helical strip 11. One of its functions is to adhere to thewarpstrips 12, bridging the outwardly-exposed squares or patches of thehelical weft 11, and thereby preventing the latter from raveling at acut end of the conduit.

I claim 1. An insulating-conduit for electric wires consisting ofcircumferential elements, and longitudinal, substantially flatwarp-strips interwoven therewith and composed of smooth, flexible,compact, insulating material.

2. An insulating-conduit for electric Wires consisting of substantiallyflat circumferential elements composed of smooth, flexible, compact,insulating material, and longitudinal warp-strips of a similarcharacter. interwoven therewith. q

3. An insulating-conduit for electric wires consisting of asubstantially flat helical weftstrip composed of smooth, flexible,compact, insulating material, and longitudinal warpstrips of a similarcharacter interwoven with the weft-strip and abruptly bent in crossingthe edges of said strip.

4:. An insulating-conduit for electric wires consisting ofcircumferential elements composed of smooth, flexible, compact,insulating material, longitudinal strips of a similar characterinterwoven with said elements, and an inclosing adhesive wrappingadhering to said longitudinal strips.

5. An insulating-conduit for electric wires consisting of a helixcomposed of smooth, flexible, compact, insulating material, longitudinalstrips of a similar character interwoven therewith, and one or morelongitudinal lockingthreads.

6. An insulating-conduit for electric wires having an interior exposedsurface consisting of interwoven strips, composed of smooth, flexible,compact insulating material.

In testimony whereof I have aflixed my signature in presence of twowitnesses.

ARCHIBALD T. BLACKLER.

Witnesses:

R. M. PiERsoN, JAMES S. ILsoN.

